<script setup>
import {ref,watch} from 'vue'
import { useMouseInElement } from '@vueuse/core'
// props适配图片列表
const props=defineProps({
    imageList:{
        type:Array,
        default:()=>[]
    }
})
// // 图片列表
// const imageList = [
//   "https://yanxuan-item.nosdn.127.net/d917c92e663c5ed0bb577c7ded73e4ec.png",
//   "https://yanxuan-item.nosdn.127.net/e801b9572f0b0c02a52952b01adab967.jpg",
//   "https://yanxuan-item.nosdn.127.net/b52c447ad472d51adbdde1a83f550ac2.jpg",
//   "https://yanxuan-item.nosdn.127.net/f93243224dc37674dfca5874fe089c60.jpg",
//   "https://yanxuan-item.nosdn.127.net/f881cfe7de9a576aaeea6ee0d1d24823.jpg"
// ]
// 获得鼠标相对位置
const target=ref(null)
const { elementX, elementY, isOutside } = useMouseInElement(target)
// 控制滑块跟随鼠标移动(监听elementX, elementY变化,一旦变化则重新设置left/top)
const left=ref(0)
const top=ref(0)

const positionX=ref(0)
const positionY=ref(0)
watch([elementX, elementY,isOutside], () => {
    // 如果鼠标不在盒子里面 则不执行以下逻辑
    if(isOutside.value) return
  if(elementX.value<100){
    left.value=0
    }else if(elementX.value>300){
      left.value=200
      }else{
        left.value=elementX.value-100
        }

    if(elementY.value<100){
      top.value=0
      }else if(elementY.value>300){
        top.value=200
        }else{
          top.value=elementY.value-100
          }
    // 控制大图的显示
    // 大图的移动方向和滑块相反 且数值为两倍
    positionX.value=-2*left.value
    positionY.value=-2*top.value
})

const activeIndex=ref(0)
const enterHandler=(index)=>{
  activeIndex.value=index
}
</script>


<template>
  <div class="goods-image">
    <!-- 左侧大图-->
    <div class="middle" ref="target">
      <img :src="props.imageList[activeIndex]" alt="" />
      <!-- 蒙层小滑块 -->
      <div v-show="!isOutside" class="layer" :style="{ left: `${left}px`, top: `${top}px` }" ></div>
    </div>
    <!-- 小图列表 -->
    <ul class="small">
      <li v-for="(img, i) in props.imageList" :key="i" @mouseenter="enterHandler(i)" :class="{active:i===activeIndex}">
        <img :src="img" alt=""  />
      </li>
    </ul>
    <!-- 放大镜大图 -->
    <div class="large" :style="[
      {
        backgroundImage: `url(${props.imageList[activeIndex]})`,
        backgroundPositionX: `-${positionX}px`,
        backgroundPositionY: `${positionY}px`,
      },
    ]" v-show="!isOutside"></div>
  </div>
</template>

<style scoped lang="scss">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;

  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
  }

  .large {
    position: absolute;
    top: 0;
    left: 412px;
    width: 400px;
    height: 400px;
    z-index: 500;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    background-repeat: no-repeat;
    // 背景图:盒子的大小 = 2:1  将来控制背景图的移动来实现放大的效果查看 background-position
    background-size: 800px 800px;
    background-color: #f8f8f8;
  }

  .layer {
    width: 200px;
    height: 200px;
    background: rgba(0, 0, 0, 0.2);
    // 绝对定位 然后跟随咱们鼠标控制left和top属性就可以让滑块移动起来
    left: 0;
    top: 0;
    position: absolute;
  }

  .small {
    width: 80px;

    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;

      &:hover,
      &.active {
        border: 2px solid $xtxColor;
      }
    }
  }
}
</style>